IMPERIAL BEACH, Calif. – The county’s Department of Environmental Health Saturday advised swimmers, surfers and other ocean-goers to stay away from beaches in San Diego County because urban runoff from this week’s rainfall had possibly increased bacteria levels.
According to the DEH, activities such as swimming, surfing and diving should be avoided in areas, including all coastal beaches, Mission Bay and San Diego Bay, for 72 hours following rain.
Elevated bacteria levels could persist following a rainstorm depending on the intensity of the storm, the volume of runoff and ocean conditions.
The DEH issued a general advisory for the county’s coastal waters warning that bacteria levels can rise significantly in ocean and bay waters, especially near storm drains, creeks, rivers and lagoon outlets that discharge urban runoff.
The runoff could contain large amounts of bacteria from various sources including animal waste, soil and decomposing vegetation, DEH officials said.
Many coastal storm drains were permanently posted with white metal warning signs, and additional signage is not posted for general advisories, according to the DEH.
Recent rainfall also prompted officials to suspect ocean currents brought sewage-contaminated runoff from the Tijuana River that had entered the Tijuana Estuary north toward Imperial Beach, prompting a water contact closure, according to the DEH.
The water contact closure area at the Tijuana Slough National Wildlife Refuge was expanded north to Carnation Avenue.
Signs posted that warned of the contaminated water will remain in place until field measurements indicated the ocean water was safe for recreational use, DEH officials said.